1. Technical Field of the Invention
The present invention relates to a technique for creating acoustic effects simulative of various kinds of acoustic spaces such as a concert hall and a theater and for applying the crated acoustic effects to sounds to be reproduced in other spaces than these acoustic spaces.
2. Prior Art
A technique is conventionally known which reproduces, in a room at user's home or the like (hereafter called a “listening room”), an acoustic space where a sound generating point for emitting sound and a sound receiving point for receiving the sound emitted from the sound generating point are arranged. The use of this technique allows the user to listen to realistic music in his or her listening room as if he or she were enjoying a live performance in a concert hall or theater.
For example, as one of techniques for reproducing a desired sound field, there is a method of determining an impulse response based on various parameters, and convoluting the impulse response into an audio signal representing the music sound to be reproduced. The various parameters characterizing the sound field to be reproduced include the shape of an acoustic space, the arrangement of a sound generating point and sound receiving point, and so on.
More recently, there has been studied an advanced technique for reflecting directional characteristics of the sound generating point or sound receiving point in reproducing a sound field (for example, see Patent Document 1). Under this technique, an impulse response representing the directional characteristics of the sound generating point or sound receiving point is used in the convolution operation, in addition to other parameters such as the shape of the acoustic space and the arrangement of the sound generating point and the sound receiving point. It allows the reproduction of an acoustic space with a great sense of realism.
Patent Document 1 is Japanese Patent Laid-Open No. 2001-125578. The related description is found in Paragraph 0020 of Patent Document 1.
When reproducing a desired acoustic field in the manner as mentioned above, if the user can change the arrangement and further orientation of the sound generating point or sound receiving point as needed, a sound field desired by the user can be reproduced in real time with a great sense of realism. In this case, however, the user is required to specify both the position and the orientation of the sound generating point or sound receiving point each time he or she changes these points. For example, when wanting to change the orientation of the sound receiving point with the movement of the sound generating point, the user needs to perform complicated instructive operations, such as to change the orientation of the sound receiving point at the same time as moving the sound generating point, thereby causing heavy burden on the user.